This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Understanding the precise mechanism of how microbial pathogens disrupt critical cellular function leads not only to successful treatment of infections, but also gives scientists powerful tools to probe fundamental cellular processes. In this project, we will investigate how a group of bacterial toxins [unreadable]botulinum neurotoxins (BoNTs) [unreadable]induces degeneration of neurons. The goal is to uncover the presynaptic function, targeted by BoNTs, that is essential for maintaining the integrity of axons and survival of neurons.